How long does it take me to gain weight I want to gain about 30 or 40 pounds and I weigh 115 I'm a teen and I want to gain weight in about 2 months Can I gain that much by then?

Honestly it depends if you have been having a hard time gaining weight then it probably means you have a fast metabolism which is a good thing and wont last forever, enjoy it while you are a teen. Anyway if you really want to gain weight then increase your calorie intake and carbs. It might not necessarily work considering i know some people who had high metabolisms who tried to gain weight and ate ice cream and stuff and it didnt help at all. But my best advice is increase what your eating, try to keep it healthy though so you dont become unhealthy through the gaining of weight.